Plank abdomen refers to acute diffuse peritonitis due to acute gastrointestinal perforation or organ rupture, where the peritoneum is irritated and causes spasm of the abdominal muscles, and the abdominal wall is often markedly tense and even straight and hard like a plank, hence the name. For example, acute gastrointestinal perforation, acute necrotizing pancreatitis, intestinal perforation, acute appendicitis, or organ rupture, as well as gynecological diseases may occur. In severe cases, it can cause a drop in blood pressure and systemic toxic reaction, and if not treated in time, it can lead to death by toxic shock. Some patients may have pelvic abscess, inter-intestinal abscess, and subphrenic abscess, iliac fossa abscess, and adhesive bowel obstruction. Causes of lamellar abdomen: Bacteria can cause the development of primary lamellar abdomen. Bacteria can enter the abdominal cavity by four routes: 1. Hematogenous dissemination: pathogenic bacteria reach the abdominal cavity by hematogenous dissemination through foci of infection in the respiratory or urinary system. Most of the primary laminitis in infants and children belong to this category. 2, Upstream infection: bacteria from the female genital tract spread directly upstream through the fallopian tubes to the abdominal cavity, resulting in lamellar abdomen. 3, direct diffusion: such as urinary tract infection when bacteria can spread directly through the peritoneum to the abdominal cavity. 4, intestinal bacterial translocation: the basis of its pathology is more liver sclerosis, long-term fasting, malnutrition when the body resistance is weak, bacteria and endotoxin through the intestinal wall into the abdominal cavity thus causing diffuse lamellar abdomen.